The best composting toilets for campervans, RVs, sailboats and tiny homes

Human beings love avoiding the “ick” factor when it comes to dealing with pee and poop. Out of sight, out of mind is often our motto. Luckily, a composting toilet does keep waste hidden away and smell free.

A composting toilet can be a great solution for people who live off-the-grid or on the go.

Maybe you’re an RVer who’s sick of dealing with a nasty blackwater tank and finding places to dump your poo.

A good composting toilet might be just the ticket to solve all your dumping needs.

What is a composting toilet?

For eons, people have been trying to figure out just how to deal with their #1 and #2. The waterless toilet system started in ancient China, where rumor has it they stored human waste in ceramic containers to destroy any parasites. They’d then dump that waste on their soil, as fertilizer. Hence the very first composting toilet.

Our more modern edition of the composting toilet was commercialized by the Clivus Multrum company in Sweden in the 1960s. Then, in the 1970s, another Swedish company called Biolet started manufacturing composting toilets on a larger scale.

The composting toilet is special because it uses natural elements to compost human waste; no water is necessary.

Bacteria and bulking agents are mixed with human waste to create compost over time, which is called humus. If the toilet is maintained properly, the toilet will compact waste to 10-30% its original volume. Then, you can use that humus as fertilizer, bury it, or throw it away depending on your state or city’s regulations.

Read on to learn the specifics of how a composting toilet works.

How does a composting toilet work?

A composting toilet needs three main elements to properly digest your waste: moisture, warmth and oxygen.

After you use the composting toilet, you add a scoopful of bulking agent to the bowl, which is anything from peat mix, to coconut fibers, to straw or sawdust. You turn a handle to mix it all together, or some toilets do this themselves.

Once everything is mixed together, anaerobic bacteria use oxygen to break down the waste. It works a lot like your backyard compost pile.

The toilet needs to evaporate excess moisture to work, so many toilets have separate containers for #1 and #2. If that’s the case, you dump the urine separately, then wait for the #2 to become compost.

It’s important that the bacteria have enough oxygen and moisture to work correctly, and the toilet also has to be at the proper temperature, somewhere above 55 degrees. If the temperature gets below 55 degrees, the toilet will just pause in its composting and resume when it heats back up again.

According to Let’s Go Green: “The correct balance between oxygen, moisture, heat and organic material is needed to ensure a rich environment for the aerobic bacteria that transform the waste into fertilizing soil. This ensures odor-free operation and complete decomposition of waste.”

When your waste is done composting, the toilet has a finishing chamber or drawer, so you can easier slide the compost out and dump it according to your state’s regulations.

Why you need a composting toilet

A post shared by Andrea CF (@fiskybusiness89) on May 22, 2018 at 5:20pm PDT

Composting toilets solve a lot of problems for people and the environment. Take a moment to think about how much water a traditional toilet needs for flushing. Some of the older models use 7 gallons every flush. That is insane! Luckily, the newer toilets use far less – a little over one gallon – but that’s still a ton of water.

According to Conserve H20, more than 47% of water use in the average American home occurs in the bathroom, with nearly 24% being used by toilets.

But when it comes to composting toilets, the environmental impacts are actually positive. In fact, one person using a composting toilet for one year creates 80 pounds of compost and saves 6,600 gallons of water per year. Holy crap!

Besides the environmental impacts, using a composting toilet also has a positive impact on your pocketbook. Your water bills will go way down, and if you’re building a tiny home, you won’t have to pay to get hooked up to the city water and sewer system.

Van lifers, RVers and sailors also love composting toilets due to their ease of use and lack of odor. It’s awesome not having to head to a pump out station, or deal with chemicals.

The negatives of a composting toilet

Yes, even though there are many positives about using a composting toilet in your van, RV, sailboat or tiny home, there are also negatives to be aware of before you buy. Composting toilets are expensive, so it’s good to have all the information and weigh your options to find the solution that best fits your needs.

If you don’t handle your compost correctly, it could make you sick. You have to wait the correct amount of time to move the compost to make sure the pathogens from your poo are no longer there

Composting toilets require more maintenance than traditional toilets

The toilets could stink if not properly maintained

Most composting systems require a power source

If you don’t properly set up the ventilation system for your composting toilet, bugs and insects could get in there (ew!)

They are much more expensive than other toilet systems

They are not meant to be moved around

Good food for thought if you’re thinking of a composting toilet.

Do composting toilets stink?

Photo courtesy Nature’s Head

A lot of people wonder if composting toilets stink, and the answer is this: no. That is, if they’re installed, maintained, and properly ventilated they do not stink.

A composting toilet that’s functioning properly should have absolutely no odor, and here is why:

Aerobic bacteria break down your waste, which produces odorless carbon and water vapor. Another type of bacteria, called anaerobic bacteria smell really bad because they excrete methane, ammonia and hydrogen sulfide

Composting toilets also seal off the moment after you use them, which keeps the waste and any potential odors safely tucked away. Also, a ventilation system keeps moving the odor out of the container where all the magic happens. If the vents are properly routed outdoors, no nasty fumes will enter your living space.

The different types of composting toilets

There are two main types of composting toilets: self-contained and central systems.

Self-contained composting toilets are the type you’d see used in a van or an RV. There’s the toilet, the bowl, and right under is the container where the composting happens.

With a central composting system, your toilet is in one room, and the composting chamber is located in another room. This is often done in a house, as it looks most like a regular toilet and the composting is kept far away from the bathroom.

For this review, we’re going to stick with self-contained composting toilets as they’re the most common for campervans, RVs, sailboats and tiny homes.

Factors to think about when picking a composting toilet

Sizing: You’ll need to make sure you have enough room in your van, RV or sailboat to install a composting toilet. Some take up more space than others, and it’s important to measure the handle and see how much room it needs to function correctly.

Installation: The composting toilet needs a way for its exhaust vent to reach the outside, so you may have to cut a hole in your rig. They are designed to bolt right to your floor, so aren’t really moveable. You’ll also need some sort of 12-volt fan to ventilate the compost, and a battery system to power that fan. In reading various RV and van life forums, installation tends to be fairly easy.

How it diverts urine: As you’ll read below, the toilets recommended divert urine into another container, so the #2 can turn into compost faster. Some of those containers are located near the main composting bowl, which you have to open briefly to grab the urine tank. The AirHead toilet keeps the urine container on the outside of the toilet, so you don’t have to disturb the main container, which might smell a little when opened.

The best composting toilets of 2018

There are so many toilets on the market right now, but there are several that stand tall above the rest. Composting toilets are designed for different needs. Some are better in vans, RVs and sailboats, and some work really well in a tiny home. In this review, we’ll walk you through the main features of each toilet, and their positives and negatives.

1. Nature’s Head Composting Toilet

Nature’s Head composting toilet with spider handle

Nature’s Head composting toilets are by far the most affordable ones on the market, and are very popular amongst van lifers, RVers and sailors. They were invented by two sailors who wanted a robust, odorless toilet for the ocean, without the need for a holding tank. These toilets, which use stainless steel hardware, can take the jostling and vibration of life on the road. They’re also small enough to fit in the tiniest space. For the price, we think this is the best choice on the market if you want a composting toilet.

This toilet is self-contained and has separate containers for pee and poop. Plus, there’s a trap door design that opens when you sit on the toilet, which eliminates the need to buy separate liners for the bowl.

There are two types of Nature’s Head Composting Toilets. The real difference between the two is the type of handle used for stirring the compost. One has a space-saving spider handle, and one has a standard crank handle.

Check out this video by Gone with the Wynn’s about why they love their Nature’s Head Composting Toilet:

2. Separett Composting Toilets

Separett is a company from Sweden getting a foothold in the U.S. market when it comes to composting toilets. They’ve been popular toilets in Europe for over a decade. Separett’s toilets are sleek and minimalistic, and most-closely mimic a normal toilet. According to Separett’s website, their toilets “overcome the ‘visual acceptance’ hurdle of changing toilet systems.”

A huge difference between Separett and the other options listed here is that the composting doesn’t happen inside the toilet. Instead, you remove the biodegradable bag and put it somewhere else, like in the ground or a separate composting pile so it can continue composting.

Another huge difference between this toilet and others is the urine is piped somewhere else, so if you’re in an RV, you’ll need to divert it to your greywater tank. In a tiny house, the urine can be diverted outside.

Separett manufactures three toilets: The Villa 1920 AC, The Villa 1920 AC/DC and the Weekender.

The positives of Separett composting toilets:

Urine-diverting toilet, which either runs to a greywater tank or a collection container

Includes a biodegradable bag so you can easily lift out compost and bury it

Sleek design; looks a lot like a regular toilet

Ships with all the parts you need to connect the toilet

Weight-activated trap door that prevents the user from seeing the contents of the toilet

Can be connected to both 12v DC or 110v AC power

The negatives of Separett composting toilets:

A little more expensive than Nature’s Head

The urine is diverted to a tank, container, or outside, which could make it a little more difficult for van life

We browsed many sites and forums and couldn’t find complaints on Separett toilets

To learn more about the Separett Villa DC toilet, check out this video:

3. Sun Mar Composing Toilets

Sun-Mar composting toilets ring in at twice the cost of Nature’s Head, and use a patented Bio-drum technology to compost waste. The Bio-drum is engineered with three separate compartments, each which handle a different part of the composting process. The drum keeps the moisture level constant and maintains the correct temperature. In the electric unit, a fan draws air in, and a vent chimney does the work in a non-electric unit. Those ventilation systems evaporate liquid and pull in fresh air. Sun-Mar electric toilets also have a thermostatically-controlled heater, which helps with the evaporation step.

Sun-Mar is one of the original composting toilet companies; it claims its founder invented self-contained composting toilets in the early 1970s.

There are a lot of toilets to choose from if you’re interested in Sun Mar – the company makes 22 models. There are electric toilets, non-electric toilets, solar toilets, a compact toilet and a mobile toilet for the traveling lifestyle.

4. Air Head Composting Toilets

The Air Head Composting Toilet claims its the smallest composting toilet on the market, close to the size you have at your home. The toilets have a regular toilet seat and lid, and look a lot like a regular plumbed toilet. This can ease people’s fears of using a new toilet system. According to its website, Air Head says it’s the only diversion system that allows emptying of the urine bottle without opening the solids tank. Designed for marine use, the Air Head can fit in very small spaces. The toilet’s 5-gallon capacity means a liveaboard couple can expect 60 uses in a month before emptying the solids tank.

The positives of Air Head Composting toilets:

Smaller than other composting toilets on the market

You don’t have to open the solids tank to remove the urine container for dumping

No nasty streaks on the bowl; the Air Head uses a paper bowl liner that carries solid waste down to the tank

About Kristin Hanes

Kristin Hanes is a journalist and writer who lives on a sailboat and in a Chevy Astro van in San Francisco. She worked in radio news for 15 years before a massive layoff in 2016. Kristin has written articles about alternative living published in Good Housekeeping, Business Insider, Marie Claire, SF Gate and The Bold Italic, among others.

Comments

It’s amazing how much more acceptance composting heads are getting for boats and RVs. We built our own using a urine separator from Kildwick (a small British company you should definitely check out). It’s amazing how much simpler life has gotten nw that we’re not having to get frequent pumpouts of our 12 gallon holding tank.

Wow, that’s amazing you built your own! I’ve been noticing more and more people using composting toilets for RVs, vans, sailboats and tiny homes. It seems like a great option. Very environmentally friendly as well, which I like.

After the holding tank on our sailboat pooped out, we switched to an Airhead and we love it. So much better than a regular head. Once you get used to it (which doesn’t take long), you realize it is much better than a holding tank. We are int he process of buying a new boat to start full time cruising that has 2 heads and now we will have to save up to put in composting heads, but who doesn’t love boat projects centered around poop?!?!? 🙂

Hi there, im about to buy a liveaboard boat and researching this option..question is where to dispose of solids / composted waste ..if were sailing for a few weeks or more is it marine safe to dispose overboard or is that a complete no no. ..once the toxic pathogens have gone and become compost ..is that safe or best to store somewhere till back onshore..thanks for any advice

Hi Graham! I think the rules will deped on where you live. I do think in some places to can put the composted waste into a regular trash bin. If you’re out sailing, you can usually legally dump any human waste once you are 3 miles offshore.

With the composting toilet issue it may be worth talking to an RV sales group if you are looking at putting a composting toilet into an RV that you will be looking at selling. You may find the toilet dramatically limits the number of possible byers and consequently the resale value. The reconversion to a traditional system is not cheap either.

[…] This drying process activates the composting process. If the head is used correctly, the waste doesn’t contain any pathogens or viruses – they are destroyed by bacterial breakdown – and there is no odor. For more detailed information on composting toilets, check out this article. […]

Hi, I'm Kristin Hanes! I live in a sailboat and in a van, and am editor-in-chief of The Wayward Home, a site all about a new type of American Dream. Stick around to learn about campervans, RV living, sailboats and tiny homes. Head to my About Me page to learn more.

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